Motor compressor unit



Feb. 20, 1951 H. E. EARL MOTOR COMPRESSOR UNIT Filed Sept. 9, 1947 INVENTOR. HOWARD E. EARL Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE MOTOR COMPRESSOR UNIT Application September 9, 1947, Serial No. 772,970

3 Claims. (Cl. 230-114) This invention relates to motor compressor units and has particular relation to a motor compressor unit in which a motor, a centrifugal fan, and a fuel and primary air pump unit are employed as a single unit for supplying the primary mixture and secondary air employed in the operation of low pressure oil burners.

An object of the invention is to provide a simple, reliable and inexpensive unit of this kind in which the unit may be employed in connection with installations requiring oil burners of different capacities, merely by adjusting a unit in such a way as to alter the capacity thereof.

Another object of the invention is to provide a motor compressor unit of this kind in which the unit will perform satisfactorily when used in connection with oil burner installations of different capacities.

Other and further objects of the invention will be apparent by reference to the accompanying drawings of which there is one sheet, which by way of illustration shows a preferred embodiment and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. I also contemplate that of the several different features of my invention certain ones thereof may beadvantageously employed in some applications separate and apart from the remainder of the features.

In the drawings:

Fig. 1 illustrates a side elevational View partly in cross section of a motor compressor unit embracing the principles of the invention;

Fig. 2 is an enlarged fragmentary longitudinal sectional view of the shaft employed in the motor compressor unit illustrated by Fig. 1 and illustrating particularly the centrifugal fan adjusting means disposed axially within the shaft;

Fig. 3 is a transverse sectional view through the centrifugal fan employed in the motor compressor unit illustrated by Fig. 1; and

Fig. 4 is a fragmentary view of one end of the motor compressor unit shown by Fig. 1 and illustrating particularly a cover for the centrifugal fan adjusting means illustrated by Figs. 1 and 2.

Referring particularly to Fig. 1, there is illustrated a motor compressor unit indicated generally by the numeral III. The unit It comprises a motor compressor unit casing II consisting of a central support portion l2 having a pair of end casings I3 and I4 projecting in opposite directions therefrom. The end casing I3 encloses a motor I4 mounted on a shaft I6 which extends from within the casing I3 transversely across the central casing I2 and into the opposite end casing I I.

The end or motor casing I3 includes bearings I1 and I8 formed at opposite ends thereof in which the shaft I6 is rotatably mounted. End wall I9 supports the bearing I1 and separates the end casing I3 from the centrally disposed support section I2 of the casing I0. Disposed on the portion of the shaft I6 which projects within the casing portion I2 is a centrifugal fan 2I having a disc shape end 22 which is supported by a collar 23 rigidly secured on the shaft by a set screw 24. Secured to the flanged periphery of the disc 22 is a circular member 28 which is transversely slotted to provide angularly disposed vanes 21. The opposite end of the circular member 26 is likewise secured upon the flanged periphery of a supporting ring 28 provided with a centrally disposed opening 29 forming the fan inlet.

Rotation of the fan 2| by the motor I4 will cause air to be drawn inwardly of the fan 2I through the inlet 29 there to be discharged by the vanes 21 radially outwardly into the interior of the central casing I2 surrounding the fan. The space surrounding the fan 2 I within the central casing I2 is formed to provide a scroll 30 of progressively increasing cross section around the periphery of the fan and leading to a fan outlet 3| where the air under pressure supplied by the fan is discharged from the fan casing I2 into the oil burner 32 to which the motor compressor unit I0 is secured. The scroll 30 within the fan casing I2 is separated from the fan inlet .29 by an inwardly projecting flange 33 formed on the fan casing I2, the end of which terminates adjacent the outside surface of the end ring 28.

Beyond the fan casing I2 the shaft I6 includes a universal coupling 34 by which a reduced portion 36 of the shaft is connected to the main portion thereof. Such reduced portion 36 of the shaft I6 extends beyond the coupling 34 across the casing end I4 and there drives a pump unit indicated generally at 31. When rotated by the shaft I6 the pump unit 31 is adapted to compress a small quantity of primary air, to pump and measure quantities of fuel to be mixed therewith, and all of which is supplied to the burner 32 to be there burned with the secondary air supplied by the fan outlet 3|. Since specific details of the pump unit 31 form no part of the present invention, the pump 31 may therefore comprise any kind of pump unit which it may be desired to employ. Nevertheless, a pump unit of a similar type is disclosed by the copending application of Robert R. Witherell, Serial No. 706,139, filed October 28, 1946, and assigned to the assignee of 'the present application.

In order tor-provide a' suificient quantity "of air for operating the centrifugal fan 2| under all possible operating conditions, the end casing I4 is provided with a plurality of openings 38.which admit air to the interior of the flange ring32 to be supplied to the centrifugal. fan inlet 29.

In order to be able to vary the'eifectivelength of the vanes 21 and consequently the capacity of the fan 2i for delivering-air to the outlet 3.1, there is provided inwardly of the'vanesfil an axially movable bafile as. The baflle 39. comprises a frusto-conical disc .5! 1 periphery upon a collar 42 adapted to slide longitudinally of-the'shaft I6 from the end of collar 23' supporting the fan to the end of the universal coupling 33. In order to provide .meansforadjusting the position of the'baiile .35), such portion .of. the. shaft- H5 is provided with an elongated diametrically formed slot 43 having a pindioxtending thereacross and projecting into diametri- ..cally .opposed openings formed in-.- the ring 42. The pin M is secured in positionwithin such ropenings by a snap ring- 45 which is disposed in .:a c-ircumferential groove formed around the-collar 42. The central portion of the pin projects through an opening formed-transversely across .the' end of a small actuating shaft or rod l Which-is disposed in an opening 38 formed axially Within the shaft it. The rod projects through xthe=opening EB-toward the 'motor end of; the shaft i6 and in such region is-threaded as is .indicated at i --threaded portion 5% formed at one end of. a 'rotary adjusting member 52 rotatably disposed in -an-enlarged concentric-portion 53 of the opening :48. The enlarged portion or opening 53 terminates at the motor end of the shaft I6 within 1-.thefbearing i8 and is accessible .i'romthez'end of .the casing I3 through the bearing opening 5%. -A cover 62 is provided for rendering the open- .ing accessible or inaccessible as desired.

The rotary member 52 is held in position within the opening. 53 between a spring washer 56 dis- -posed at one end thereof against a shoulder formed between. two diiferent sections of the :axial opening-i8 and asnap ringtlvdisposed in a- .'g"roove formed adjacent theouters-end of the opening. 53. Beyond the :threaded portion 5I::which-. cooperates with the threaded portion 49 of ..the rod.= il, the interior of the rotary member..52. is proi'ided withan enlargedaxialopening: 58 which terminates at the: outer. end-brothe rotarymemberfiSZ and Which'provides clearance for. the threaded portion of the rod dl extending within the interior of the rotary member. 52. iBeyond theend of the rod 31 the opening 58 in-the rotary. member 52 isclosedby a diametrically slotted plug 6! which is secured rigidly within the endi-of the' rotary. member 52 in. any suitable manner.

The slotted end of the plug is accessible through the bearing opening Miinthe .casingiend Il3.-for the insertion of a screwdriver or;.other; suitable ..means by which the rotary-member 52 :may-be rotated withinthe-shaft It. When themember g 52 is rotated, assuming the shaft I6 and the rod tobestationary at such time, :therod -49 .willfor operative associationwitha .4 be moved axially within the shaft l6 by the operatively associated threaded portions of the rotary member 52 and the rod 41. The threaded portion 49 of the rod 41 is of sufficient length to move the bafiie 39 from one end to the other of the centrifugal fan 2| and consequently to render ineffective any desired portion of the length of thevane. 21., However,..*the portion" of the vanes knot v rendered ineffectiveiby being cutt'oif from the inlet by the baflie 39 continue to deliver air ..from the periphery of the fan M at the same velocity and pressure as such part of the vanes wo'ulddeliver air were the baille not employed.

With1such provision for varying the effectiveness of the vanes 21, it is possible to employ the -motoroompressor unit In with any size oil burner secured at its inner 2 .Lbelowthe. maximum capacity of the unit in with an efiiciency practically equal to the eificiency of anyfractional size unit that might be constructed. It is not necessary, however, to manu- -facture such fractional size units because ?.the zunitl 01 can be manufactured and employeda with an oil burnerrequired' to deliver any-amount of heat requiring all or a fraction of the full capacity of.- the unit 0. Undersuch. circumstances lit :is necessary only to. open the cover Bland toadjust the' position of the'rotary member 52" in such away as -to position the *bafile- 39-Within--the centrifugal fan?! to give,- the desired capacity for 'theoitburner'with' which the'unit is to' begemployed. "Thereafter the cover" 62' may be: closed, "thusrendering inaccessiblethe"means for adjustingthe capacity :of the fani2l' andfclosing the; end casing 13' to protect the 'motor lfland ,the, bearings I1 and 1.8 from exposure to .dirt

and moisture.

"While I have illustrated andldescr'ibedapreferred. embodiment. of. myinventiomit is understood-that this is .capable. of. modification, and

.I-.:therefore do not wish .to-be limited to the .pre-

cise .detailsset. forth, but desire -.to" avail myself .ofn-such changes. and alterations .as. fall within the: purview of the following. claims.

. claim:

1. .In an: -oil burner-a centrifugal .fanwasing having an air inlet in one sidethereof, .a motor .-secured-.at:one: side of said casingand provided ewitha :hollow shaft having a slottedend proejecting into saidcasin a'centrifugalzfan coma-pri-sing a blower wheelmounted on the :slotted end-of-saidxshaft so as'to be driven Etherebyarid having axially extending blades and a an, open *side, presented-toward said air. inlet, an air-adefleeting bafiieiyarranged within said wheel-rand comprising a circular member imountedronzsaid --shaft-.1transv erselythereof and for. movement axially .of said shaft toward and away -f-rom said opening,- saidcircular member: being -.concentric with said-blower-wheel and" shaft .and" extend- -ing into close-proximity with' -said blades; and being shiftable axially of-said wheel so aasto increase or .decreasethe. efiectiverlength of said wheelgandlto shut off the: supply of air-to those .-portions of saidblades onuthe side-ofzsaidmem- .75aaxially: relative -to ,said. shaft :in order to.= adjust the position of said baffle relative to said blower wheel and to said opening.

2. A device according to claim 1 wherein said member is shaped so as to have a central apex projecting toward said air inlet and said member is arranged so as to direct the air which flows axially into said blower wheel through said opening radially outward toward the blades of said wheel.

3. A device according to claim 1 wherein said 10 means for moving said rod axially relative to said shaft includes threads on the end of said rod remote from the connection between said rod and said bafile, and rotary threaded means disposed in said shaft and in threaded engagement with said rod and operable upon rotation of said threaded means for shifting said rod and bafiie axially of said shaft.

HOWARD E. EARL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

